Sickle grinder



Sept. 11, 1956 E. M. sci-:MAUS 2,752,159

l SICKLE GRINDER Filed May 27, 1955 2 Sheets-Sheet 1 1N VE NTOR f/G- 2 fm1/Ae@ M. `scf/MA as 7zvf/zm, @um ,0

y y ATTORNEYS E. M. SCHMAUS SICKLE GRINDER sept. 11, 1956 Filed May 27, 1955 2 Sheets-Sheet 2 INVENTOR E D14/AED Al. SCW/M405 ATTORNEYS United States Patent Office 2,762,169 Patented Sept. 11, 1956 SICKLE GRINDER Edward M. Schmaus, Sisseton, S. Dak. Application May 27, 1955, Serial No. 511,598 3 Claims. (Cl. 51-33) This invention relates generally to improvements in grinders for such as sickle blades.

It is an object of this grinder for sharpening of sickle blades wherein a sickle blade, once secured in the grinder, is set for the sharpening of a number of teeth of the sickle blade before requiring resetting of the sickle blade for the sharpening of other teeth thereof.

It is a further object of this invention to provide a swing grinder in which the angular position of the limited arc in which the grinder is adapted to move can be selectively adjusted so as to compensate for wear of the grinder.

Still another object is to provide a swing grinder for sickle blades wherein a blade may be quickly mounted therein and in which the grinding can be accomplished with great accuracy despite the simple, yet rugged, construction of the swing grinder.

Another and still further object of this invention is to provide in a sickle grinder, simple, yet effective, means whereby a sickle blade to be sharpened is confined to move in an arcuate path toward the grinding means, which can be selectively adjusted so as to increase the accuracy of the sharpening operation.

Other objects, features and advantages will become apparent from a consideration of the following detailed description, forming the specification, and taken in conjunction with the accompanying drawings, in which:

Figure 1 is a top plan view of a swing grinder embodying this invention;

Figure 2 is a side elevational view;

Figure 3 is a transverse, cross-sectional view taken along line 3 3 of Figure l;

. Figure 4 is a transverse, cross-sectional view taken substantially along line 4`4 of Figure l;

Figire 5 is a front elevational view taken along line 5-5 of Figure 1; andV showing a sickle bar to be sharpened secured in the work holding means of the device, portions of the sickle bar being broken away;

Figure 6 is an enlarged transverse cross-sectional view taken substantially along line 6-6 of Figure l; Y

Figure 7 is atransverse cross-sectional view, on an enlarged scale, taken substantially along the line 7-1 of Figure 1 and Figure 8 is `an enlarged cross-sectional view taken along line 8 8V of Figure l.. i y

With continued reference to the drawings, the illustrated device vcomprises a base frame generally indicated at 10, which includesv'a pair of spaced, parallel, longitudinalangle iron side bars 12 and 14, an angle cross brace member 16 extending therebetween at one` `end thereof,.lwith the horizontal flange of the cross brace member disposed upon the top of the horizontally extending flanges of the elongated side bars 12 and 14.

Adjacent their other ends, the side bars 12 and 14 have their vertically extending anges cut away as at 18, a transverse angle iron brace 20 'has its horizontally disposed ange secured to the undersides of the horizontal invention to provide a swingflanges of the side bars 12 and 14 at said other ends thereof yin any suitable manner. The vertical flange of the transverse brace 2G depends from the side bars 12 land 14 and provides a stop member for the base frame when the base frame is placed upon a supporting surface, such as a table top.

A Hat, plate-like horizontally disposed base plate, generally indicated at 22, is mounted intermediate its ends upon a shaft 23 extending transversely of the base frame 10 and thereabove, and journaled at its opposite ends in the upper ends of transversely aligned fixed standards 24 and 26 rising from the side bars 12 and 14. Thus, the base plate 22 is mounted to rock about the horizontal axis of the shaft 23.

Means whereby the base plate 22 may be caused to rock in a limited arc is provided by a shaft 28 extending transversely across the top of the base plate at a location between the shaft 23 and the forward end of the base frame 10 carrying the transverse brace 20. The shaft 28 is journaled in upstanding bearing blocks 30 disposed adjacent opposite longitudinal edges of the base plate 22. One end 32 of the shaft 28 is formed as a crank, while the other end 34 thereof extends outwardly from the adjacent side of the base plate. A pitman 36 has one end thereof pivotally connected to the crank 32 and the other end thereof pivoted on the upper end of the top of an upstanding plate 38 secured to the vertical ange of the base frame side bar 12 for vertical adjustment thereon by means of bolts 40 secured to the side bar 12 passing through vertical slot 41 in the plate 38, for a purpose which is hereinafter disclosed. Rotation of the shaft 28 thereby imparts rocking movement to the base plate 22 in a limited arc.

imparting rotation to the shaft 28 is a source of power, shown as an electric motor 42 which is mounted on the base plate 22 behind the shaft 23, with its shaft disposed transversely of the base plate. It will be noted that the motor 42 is preferably secured upon the upper surface of the base plate 22 so that the axis of its shaft is vertically aligned with the axis of the shaft 23.

The motor shaft 43 extends from one side of the motor and outwardly of the side of the base plate remote from theV crank 32 extends, and has xed thereon a pulley wheel 44, and a drive belt 46 is trained about the pulley wheel 44 and extends longitudinally of the support 22 toward the forward end 21 thereof and is trained about a pulley wheel 48 of approximately the same size which is secured upon a transversely extending shaft 50 journaled in a bearing block 52 mounted on the top of the base plate at the forward end of the base plate and at one side thereof. The shaft 50 is disposed parallel to the shaft 28 and to the motor Shaft 43, and has a free end portion which extends toward the opposite siderof the base plate 22 and across an opening 54 provided in the base plate 22, which cut-out portion or opening extends through the said other side of the base plate and through the forward end thereof, as clearly shown in FigureV 1. A grinding drum 56 which tapers from its middle toward its opposite ends is secured on the free end portion of the shaft 50 for rotation therewi and the grinding drum is disposed within the opening 54.V

A second pulley wheel 58 is secured upon the motor shaft 43 and has a pulley belt 60 trained thereabout. The pulley belt 60 is also trained about a considerably larger pulley wheel 62 secured upon a transversely extendingshaft 64, which is parallel to the shaft 28, and is disposedv behind the motor 42 and mounted upon the top of the base plate 22. The shaft 64 is journaled adjacent is opposite ends in bearing blocks 66 mounted on the upper surface of the base plate 22 adjacent opposite sides thereof and extending therefrom. The shaft Y 'eraton provided in connection with the stub shaft 82 whereby Y free lower end 64 has an end portion 65 extending beyond a side of the base plate Y22 upon which a pulley wheel 62 is mounted, and a smaller'pulley wheel 68 is secured on the shaft 64 outwardlyV of therpulley wheel 62 and has trained thereover a belt 70. 1 The pulley wheel 68 VVis of a size considerably Vsmaller than the pulley wheel 62. Their-belt V70 is also trained abouta considerably larger pulley Vwheel 72 lsecured'upon the outwardly extending portion S6 Vis 'rotated at a relatively high 22 is rockedY at a relatively low speed because ofthe described belt and pulley wheel arrangements.y

A grinding drum guard 74, in the form of an arcuate plate, is carried by the transverse edge of the opening 54 and is spaced from the adjacent side of the grinding drum, as shown in `Figure 2. i

On the end of the shaft 64, remote from the pulley wheel 62, there is secured a pulley wheel 76 with a drive 'belt 78 trained therearound and around a smaller size pulley wheel V80 secured upon a stub shaft 82 parallel to the shaft 64 and journaled in a bearing supported on the base plate 22 adjacent the rear end of the base plate. The shaft 82 is arranged for attachment to a flexiblershaft 84 to Vimpart rotation thereto so that the shaft 84 can be employed yfor purposes to be' determined'by the op- VAn arrangement, generally indicated at Y86, is

this shaft, and its mountings, are pivotally mounted upon the upper lsurface of the base plate 22 for movement toward and away from the shaft 64 so that when the shaft 82 is moved away from the shaft 64, the belt 78 will be tightened and rotation will be imparted to the structure while movement of the shaft 82 inthe opposite direction willloosen the belt 78 andno rotation will be imparted thereto. In order to maintain the driving connection between the shafts 64 and 82, there is provided a pivotally mounted lever 88 having a laterally, inwardly extending portion 90 adapted to engage, in the manbehind an extension 92y extending rearwardly from the rear end of the base plate 22. A Vertical helical spring 94 is compressed between the bight portion 89 of the lever 88 and the upper surface ofthe extension 92 whereby the clip portion 90 will maintain its engagement with the extension 92 and hold the vstub shaft 82 in a rearward position so that the Vbelt 78 will be maintained Vin a tightened driving condition.

It willy be noted that the opposite ends of the angle ner of a clip,

iron transverse brace on the front end of the frame 10V Y extend beyond the side bars`12 and `14 and havelmounted thereon upstanding bearings 96 in'which are journaled opposite ends of a shaft 98, on which a work holding assembly, generally indicated at 100, is mounted to rock toward and away from intersecting relation with the grinding drum 56.

TheY work holding assembly 100 comprises a pair of plate-like standards 102 and 104 rotatably secured at their lower ends on the shaft 98 outwardly of and adjacent the bearing brackets 96, as seen in Figure 5.

A guide rod 106 extends between and is supported at its opposite ends inthe upper ends of the .standards 102 and 104` and extends parallel to the shaft V98. A work support, generally indicated at V108, is carried on the guide rod 106 for sliding movement therealong from a point adjacentto the standard 102 to a point adjacent to the standard 104. A sickle bar, generally indicated Vat 110, having rearwardly projecting teeth 112, is carried in the work support 10S for Ymovement therewith into intersecting relation with the grinding drum 56.

The work support 108 comprises a pair of vertical, lon- 34 Vof the shaft 23, whereby rotation isY imparted to the shaft 28 and thereby to the crank `32 ,Y and to the pitman 36, so as to rock the base plate 22 Vaboutrthe shaft 23 in'a limited arc, when the motor 42 gitudinally spaced plates 114 and 116 slidably mounted adjacent their upper ends upon the guide rod 106 so as to be movable longitudinally therealong. A bar 118 extends between the spaced plates 114 and V116 adjacent the lower ends thereof. A'shaft 120 extends between the plates 114 and 116 and is journaled in the plates at a point intermediate their ends for rotation about aV hon'- zontal axis parallel to the axis lof the shaft 98.

An elongated work holding Vchannel 11'22 is secured Vto and extends across'the upper endsrof the plates 114 and 116 and is set in al-igned recesses 124 therein with its open side facing rearwardly toward 56. The `channel 122 is of right vangular formation and is provided intermediate its ends with a Y right angularly disposed work guide 126 of a length toV ex-V tend substantially between the standards 102 and 104, as clearly shown in Figure 5. The work guide 126, has a vertically extending ange V127 secured to and extending upwardly from the vinner surface of the vertical flange 127 of the work flange V12% thereof disposed in parallel relation of the horizontal flange The free longitudinal edge 12S V'of the flange 126 'terminates in a common vertical plane with Vthe related edge of the ange 123, as shown in Figure 5. The body 131 of the sickle bar is disposed in the space between the horizontal flanges 127 and 123 with a spacer block disposed therebehind totake up the remainder of the space between the rear edges of the horizontal flanges 127 and 123 and work holding channel and work guide, respectively. This will position the teeth 112 to bear against the longitudinal free edge of the work guide, and extend rearwardly therebeyond.

Y' In order to maintain the sickle bar means of pins or rivets V134, and each of the dogs 132 has on its upper end a Vlaterally and upwardly projecting contact finger 136 adapted to engage the rear edge of the sickle bar, when the sickle bar'is placed yin the work holding channel. vided withcam openings 138. Cams 140 are mounted on the shaft 120 for rotation therewithY and each cam is received in the cam opening 138'in each of the dogs 132. An operating lever 142 is secured upon the shaft 120 intermediate lits ends for imparting rotation thereto so that when the operating tion, the cams will be rotated in the cam openings 138 and position the lingers 136 of the dogs 132 against the exposed edge of the sickle bar 110 in the work holding channel 112.

A pair of upstanding to the upper ange of provides manually work holding assembly 100 may be moved in its arcuate path toward and away from intersecting relation with the grinding drum. Also, the handles 144 and 146 provide means whereby the work support'108 can be .moved longitudinally of theshaft 98 along the guide rod Y106.V

sharpened thereby as the' work support isr again moved toward the grinding drum.

In order to accurately limit the rocking of the work the grinding drum Y holding channel 122 with its horizontalV 123 of the work holding channel 12.2.V

the vertically disposed anges of the Y as shown in Figure 5,

110 in the workV holding channel, in the manner described, there is pro- The lower ends of the dogs are pro lever is moved in .one direcn handles V144 and 146V are. securedY Y the Work holding channel. This operable means whereby the entire Y the, Work .support Yalong the Y holding'assembly 100 toward the grinding wheel 56, there is provided a chain 148 secured by a stud 150 at its its lower end to the horizontally extending ange of the transverse brace 20 and at its upper end to the standard 102 adjacent the upper end thereof and immediately below the guide rod 106. The length of the chain 148 will determine the amplitude of movement of the work holding means 100 toward the grinding drum 56. The stud 150 may be threaded in and out of the transverse brace 50 so as to provide fine adjustments of the lengthv of the chain 148 and this provides adjustments of the amplitude of movement of the work support assembly 100 toward the grinding drum 56.

As an aid in preventing too free movement of the work holding assembly 100 about the shaft 98, there is provided friction brake 152 comprising a hook 153 encirclingly engaging the shaft 98. The hook 153 is on one end of a rod 154 which extends through a suitably formed opening in the bar 118 and is formed at its end remote from the hook 153 with a handle 156. A coil spring 158 is circumposed on the rod 154 and is compressed between the bar 118 and the handle 156 so as to resiliently urge the hook 152 into engagement with the shaft 98. This places a resilient pressure upon the shaft 98 and movement of the work holding assembly about the shaft will be against the friction between the hook 153 and the shaft 90 and prevent movement of the Work holding assembly about the shaft 98.

A U-shaped reinforcing bar 160 has parallel legs 162 on its opposite ends are secured to the front surface of the vertically extending flange 122 of the work holding channel 122. The bight portion 164 of the bar 160 extends across the vertical edges of the upstanding plates 114 and 116 remote from the vertical edges in which the recesses 124 are provided to supply further rigidity to the plates.

In operation, the sickle bar is secured in the work holding channel 122 of the work support 108 of the work holding means 100 in the manner hereinbefore described, by the cam actuated dogs 132. The teeth 112 of the sickle bar are then sharpened in succession by moving the work support transversely of the grinding wheel for the extent of travel of the work support. At this point, the operating lever 142 is swung to, release the dogs 132 to bring them out of engagement with the sickle bar so that the sickle bar can be moved along the work holding channel and be again secured in place by moving the operating lever 142 in the opposite direction to return the dogs 132 to holding positions. The operations of bringing the teeth 112 successively into intersecting relation with the grinding drum by rocking the work holding assembly away from and toward the grinding drum are repeated, as will the longitudinal movement of the work support, in order to bring successive teeth into intersecting relation with the grinding drum.

Thus, it will be apparent that a considerable number of teeth of the sickle bar can be sharpened in one setting, and the number of settings required will depend on the length of the sickle bar. In any event, relatively few settings will be required to sharpen all of the teeth of a sickle bar so that this may be done rapidly, eticiently and with great accuracy.

A pair of rearwardly extending hook-like clips 166 are carried by the work holding channel 122 adjacent opposite ends thereof for engaging opposite ends of a sickle bar for assisting in maintaining the sickle bar in the work holding channel.

It will also be noted that the lower ends of each of the plates 114 and 116 are recessed as at 168 to provide clearance openings in the bottom and rear edges thereof permitting free movement of the plates relative to the frame side bars 12 and 14 and about the shaft 98 along with the work holding assembly.

Referring again to the upstanding bearing plate 38,

it will be seen that in the event of wear on the grinding drum 56, the bolts, or other suitable fastening devices, 40 will be loosened and the bearing plate 138 moved upwardly in a rectilinear path to a new position and secured in the adjusted new position by again tightening the bolts 40. This will change the rocking movement of the base plate 22 so that the angle of intersection between the grinding drum and the teeth of the sickle bar is changed Yso as 'to compensate for the wear on the drum. In other words, the angular relation between the intersection of the grinding wheel 56 and the arcuate path of movement of the work holding means can be selectively changed to compensate for wear of the grinding drum 56 and thus continue accurate grinding operations on the work held in the work holding means.

While there is shown and described the preferred embodirnent of the invention, it is to be understood that the structure is susceptible to change and modification within the practicability of the invention and therefore should be limited only by the scope of the claims appended heret0.

What is claimed is:

1. In a grinder for teeth of a sickle bar, a base frame having a forward end and a rear end, a horizontal base plate overlying and spaced above said base frame, said base frame comprising longitudinal side bars, standards fixed on and rising from intermediate points of said-side bars, said standards having upper ends, means pivoting the base plate on and between the upper ends of the standards at a point intermediate the ends of the base plate, said base plate having forward and rear ends and opposite side edges, said base plate having an opening extending through its forward end and through one of its side edges, a bearing mounted on the base plate between said opening and the other side edge of the base plate, a grinding drum shaft extending crosswise of the base plateand journaled intermediate its ends in said bearing, a grinding drum fixed on one end of said shaft and positioned in said opening, rocking means acting between said base frame and said base plate for rocking the base plate relative to the elevate and depress the grinding drum relative to the base frame, motor means mounted on said base plate and operatively connected to said grinding drum shaft and said rocking means, and a sickle bar holding assembly pivotally mounted on the forward end of the base frame and forwardly of the forward end of the base plate for movement toward and away from the grinding drum, said work holding assembly comprising support structure, a horizontal sickle bar holding channel mounted on said support structure and extending crosswise of the base frame and base plate, said channel being slidable endwise relative to said structure, said channel having an open rear side facing the grinding drum, and spring pressed dog means mounted on said structure and arranged to engage a sickle bar in the channel and exposed at the open side of the channel for retaining the sickle bar in place, and lever means for retracting said dog means from the open side of the channel.

2. In a grinder for teeth of a si-ckle bar, a base frame having a forward end and a rear end, a horizontal base plate overlying and spaced above said base frame, said base frame comprising longitudinal side bars, standards fixed on and rising from intermediate points of said side bars, said standards having upper ends, means pivoting the base plate on and between the upper ends of the standards at a point intermediate the ends of the base plate, said base plate having forward and rear ends and opposite side edges, said base plate having an opening extending through its forward end and through one of its side edges, a bearing mounted on the base plate between said opening and the other side edge of the base plate, a grinding drum shaft extending crosswise of the base plate and journaled intermediate its ends in said bearing, a grinding base frame so as to alternately end .oithe basefplate for movementtoward; and away Y fromrther grinding drum,

said work holding assembly cern- Vprising,snpport structure,Y a horizontal v sickle bar holding channel mounted on 4said support structure and extend 4, Ving crosswise of the base fr me and base plate, Ysaid channel being slidable i channel having anV open rear side Vfacing the grinding endwisel relativeto said structure, said drum, and spring pressed dogkmeans mounted on Vsaid structnre and arranged to engage a sickle bar in the channel and exposed at the open side of the channel for retaining the sickle bar in place, and v*lever means for retracting said dog means from the open side of the channel,

Y and handle means on said channel for rocking said structuresy to move said channel toward and away'rfrom the grinding drum and'fcr movingV said -channel endwise rela tive to said support structure. Y

3. In a grinder for teeth of a sickle bar,V a base frame havingV a forward'end and a reary end, a horizontal base lplate'overlying and spaced above said base frame, said base frame comprising xed on and rising from intermediate points of saidside bars, said standards having upper ends, means pivotingV the base plate on and between the upper ends of the standards at a point intermediate the ends ofthe base plate, said base plate lhaving forward and rear ends and opposite side edges, said baseplate having an opening extending through its forward end and through one of its side edges, a bearing mounted on the base platerbetween said opening and theother side edge of the base plate,a grinding longitudinal side bars, standards Y depress the grindingrdrum relativeht V`means, and a sickle nre-nnted'en the forward Vfzo'n'tal sickle barv holding for rocxing said structure to drum shaftY extending-crosswise of the4 base plate, and iourmledY intermediate its @raisin said bearingi'a grinding drum -xed 0n erlernt!Y Af saidshat and pQSitonedin said @pgina c frame and saidbase plaeforrgckug thebaseplate relative 4,to the'base frame Vso as to alternately elevate and 01h@ has@ frame `motor means rnonnted on said base plate and operatively Ywnaeted tg Said ,grinding drum Shaft and aid cracking bar Yholding assembly pivotally @und @i thebas flamand folr-` lwardly of Ythe iorwardvend f the base plate for movement Y toward and away from 'the grinding drum, said YWork holding assembly comprising/supportstructure, ahori-VK r channel mountednon said supand extending crosswise. of the base frame c port structure y and base plate, saidchanncl being slidable endwise relative/to said'structure, Vsaid channel having -an' openrear Yside facing the grinding drum, and spring pressed dog means mounted on said Ystructure and arranged torenga'ge Va sickle iba'r inthe channel and exposed at theV open Yside 'of the channel lfor retaining the sickle bar in place, 'and lever means for retracting said dog means from the open side ofthe' channel, and handle means on said' channel inove said channel toward drum 'and'for moving said structure', and

and away from the grinding channel endwise' Yrelative to said support Yfriction, brake means acting between said Ybase 'iframe and said support structure and serving'to brake vagrant rocking of'said support structure;

References Cited in the'nle ofY this patent VUNITED STATES PATENTS 930,284 Haubenreisser Aug.'3, 19709 Y Y FOREIGN PATENTS 654,872 i Y FranceY ai May 26,-1'9278 vracking means acting between YSaid .baser Johnston k Ian. 1, 1901 

